IQO VERRILL 



The lower marginals form a double row, mostly two to a plate; 

 they are similar to the upper ones, but longer and mostly more 

 clavate, often with slightly gouge-shaped tips. Between the upper 

 and lower marginals, at the bases of the rays, a short intermdiate 

 row of ossicles is sometimes interpolated, and defined by a row of 

 small papular pores ; their spines are like the lower marginals, and 

 mostly stand singly. Synactinal spines are lacking ; there is a wide, 

 naked channel between the adambulacrals and inferomarginals. 



The adambulacral spines are peculiarly arranged, and look as if 

 in four rows, in adult specimens. Each plate bears two spines, or 

 alternately two and three ; but on the alternate plates, having three 

 spines, the inner spine is set on the inner edge of the plate, deep 

 within the groove, while its outer spines are at the summit, nearly 

 but not quite in line with the spines of the alternate plates. The 

 outer of these spines are situated further back, at the outer end of the 

 plates. These spines are not very slender, either tapered or clavate, 

 mostly obtuse, as long as the marginals or longer, and more slender. 

 Many of the inner ones bear small, acute major pedicellarise ; the 

 outer ones have a small cluster of minor pedicellariae. 



The apical jaw-plate bears an inner close pair of stout, tapered 

 spines, low down within the mouth, and a similar upper pair at the 

 upper margin; both pairs bear several large major pedicellariae. 



Major or forficulate pedicellariae are usually everywhere abundant, 

 scattered over the surface, between the dorsal, marginal, and actinal 

 spines, and especially on the lateral channels and interradial areas. 

 The larger ones are compressed, rather large, lanceolate or acute- 

 triangular, with a sharp or acuminate apex. Those that are scat- 

 tered on the dorsal surface are smaller, unequal in size, but similar 

 in form, though less acute. The larger and longer ones measure 

 mostly about i.oo mm. X 0.33 mm. to 0.37 mm. ; the stouter ones, 

 0.87 mm. X 0.37 mm. and 0.72 mm. X 0.39 mm. 



Minor pedicellariae, of very small size, are attached to many of the 

 spines in small groups, and are also found scattered on the dorsal 

 papular areas. 



The madreporic plate is large, convex, with numerous gyri. 



Dedicated to Dr. Richard Rathbun of the U. S. National Museum. 



The type specimens are from Maloska (Professor Kincaid). 

 ' This species is so different from any other known to me from this 

 region that no detailed comparisons seem necessary. Its finely 

 and regularly areolated surface, flaccid, reticulated dorsal skeleton, 

 and small spines will serve to distinguish it at a glance. 



